<template>
    <!-- 商品分类导航 -->
    <div class="type-nav">
        <div class="container" @mouseleave="changeIndex(-1)">
            <h2 class="all" @mouseenter="showCategory">全部商品分类</h2>
            <nav class="nav">
                <a href="###">服装城</a>
                <a href="###">美妆馆</a>
                <a href="###">尚品汇超市</a>
                <a href="###">全球购</a>
                <a href="###">闪购</a>
                <a href="###">团购</a>
                <a href="###">有趣</a>
                <a href="###">秒杀</a>
            </nav>
            <transition name="sort">
                <div class="sort" v-show="isShowCategory" @mouseleave="initNav">
                    <div class="all-sort-list2" @click="goSearch($event)">
                        <div class="item" v-for="(c1, index) in categoryList" :key="c1.categoryId" :class="{active: currentIndex === index}">
                            <h3 @mouseenter="changeIndex(index)">
                                <a :data-categoryName="c1.categoryName" :data-category1Id="c1.categoryId">{{c1.categoryName}}</a>
                            </h3>
                            <div class="item-list clearfix" :style="{display: currentIndex === index ? 'block' : 'none'}">
                                <div class="subitem" v-for="c2 in c1.categoryChild" :key="c2.categoryId">
                                    <dl class="fore">
                                        <dt>
                                            <a :data-categoryName="c2.categoryName" :data-category2Id="c2.categoryId">{{c2.categoryName}}</a>
                                        </dt>
                                        <dd>
                                            <em v-for="c3 in c2.categoryChild" :key="c3.categoryId">
                                                <a :data-categoryName="c3.categoryName" :data-category3Id="c3.categoryId">{{c3.categoryName}}</a>
                                            </em>
                                        </dd>
                                    </dl>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            </transition>
        </div>
    </div>
</template>

<script>
    import {mapState} from "vuex";
    import throttle from "lodash/throttle";
    export default {
        name: "TypeNav",
        data() {
            return {
                currentIndex: -1,
                isShowCategory: true
            }
        },
        methods: {
            // 节流处理
            changeIndex: throttle(function (index) {
                this.currentIndex = index;
            }, 50),
            goSearch(event) {
                let element = event.target;
                // console.log(element.dataset); {v-18b3c0cc: '', categoryname: '台灯', category3id: '249'}
                let {categoryname, category1id, category2id, category3id} = element.dataset;

                let location = {name: "search"};
                let query = {categoryName: categoryname};
                if (categoryname) {
                    if (category1id) {
                        query.category1Id = category1id;
                    } else if (category2id) {
                        query.category2Id = category2id;
                    } else {
                        query.category3Id = category3id;
                    }
                }

                // 判断是否有params参数
                if (this.$route.params) {
                    location.params = this.$route.params;
                }
                
                location.query = query;
                this.$router.push(location);
            },
            initNav() {
                if (this.$route.path != "/home") {
                    this.isShowCategory = false;
                }
            },
            showCategory() {
                this.isShowCategory = true;
            }
        },
        computed: {
            ...mapState({
                // 右侧函数，当使用这个计算属性的时候，会立即执行一次，state参数是vuex各个模块里面管理的数据
                categoryList: function (state) {
                    return state.home.categoryList;
                }
            })
        },
        mounted() {
            this.initNav();
        }
    }
</script>

<style scoped lang="less">
    .type-nav {
        border-bottom: 2px solid #e1251b;

        .container {
            width: 1200px;
            margin: 0 auto;
            display: flex;
            position: relative;

            .all {
                width: 210px;
                height: 45px;
                background-color: #e1251b;
                line-height: 45px;
                text-align: center;
                color: #fff;
                font-size: 14px;
                font-weight: bold;
            }

            .nav {
                a {
                    height: 45px;
                    margin: 0 22px;
                    line-height: 45px;
                    font-size: 16px;
                    color: #333;
                }
            }

            .sort {
                position: absolute;
                left: 0;
                top: 45px;
                width: 210px;
                height: 461px;
                position: absolute;
                background: #fafafa;
                z-index: 999;

                .all-sort-list2 {
                    .item {
                        h3 {
                            line-height: 30px;
                            font-size: 14px;
                            font-weight: 400;
                            overflow: hidden;
                            padding: 0 20px;
                            margin: 0;

                            a {
                                color: #333;
                                cursor: pointer;
                            }
                        }

                        .item-list {
                            display: none;
                            position: absolute;
                            width: 734px;
                            min-height: 460px;
                            background: #f7f7f7;
                            left: 210px;
                            border: 1px solid #ddd;
                            top: 0;
                            z-index: 9999 !important;

                            .subitem {
                                float: left;
                                width: 650px;
                                padding: 0 4px 0 8px;

                                dl {
                                    border-top: 1px solid #eee;
                                    padding: 6px 0;
                                    overflow: hidden;
                                    zoom: 1;

                                    &.fore {
                                        border-top: 0;
                                    }

                                    dt {
                                        float: left;
                                        width: 54px;
                                        line-height: 22px;
                                        text-align: right;
                                        padding: 3px 6px 0 0;
                                        font-weight: 700;
                                        a {
                                            cursor: pointer;
                                        }
                                    }

                                    dd {
                                        float: left;
                                        width: 415px;
                                        padding: 3px 0 0;
                                        overflow: hidden;

                                        em {
                                            float: left;
                                            height: 14px;
                                            line-height: 14px;
                                            padding: 0 8px;
                                            margin-top: 5px;
                                            border-left: 1px solid #ccc;
                                            a {
                                                cursor: pointer;
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                    .active {
                        background-color: skyblue;
                    }
                }
            }
            // 过渡动画开始状态
            .sort-enter {
                height: 0px;
            }
            // 过渡动画结束状态
            .sort-enter-to {
                height: 461px;
            }
            // 定义动画时间、速率
            .sort-enter-active {
                transition: all .5s linear;
            }
        }
    }
</style>